にしてもEven though, Even if, Even when, Also

In the same way that にしては highlights a point to be considered about (A), or simply 'while (A)', the replacement of は with the adverbial particle も will put further emphasis on (B) being a surprising or unexpected thing that accompanies (A). This continues to reflect the case marking particle に's use as a location.

にしても may be translated as 'even considering (A), (B)', or 'even while (A), (B)', and may be used with any word in its plain form. にして by itself is often considered as a stand-alone adverbial particle, despite stemming from several parts.

にしても is very regularly used with Japanese's equivalent of WH-words, like どこ, どの, だれ, なに, etc. In these cases, it highlights that 'even considering (A) is undetermined (in location, number, amount, etc), (B)'.

Caution

As opposed to としても, a grammar point that will be covered in another lesson, にしても may introduce new topics (としても may not). This is due to にしても implying that (A) and (B) exist simultaneously, without the need for (B) to necessarily stem from (A). However, としても will always imply that (B) stems from (A) in some way.